Marine & Environmental Sciences Faculty Articles

Multi-Site Evaluation of IKONOS Data for Classification of Tropical Coral Reef Environments

ORCID

0000-0002-6003-9324

ResearcherID

F-8807-2011

Document Type

Article

Publication Title

Remote Sensing of Environment

ISSN

0034-4257

Publication Date

11-2003

Keywords

Landsat, Bathymetric correction, Glint, Accuracy, Habitat mapping, Seagrass

Abstract

Ten IKONOS images of different coral reef sites distributed around the world were processed to assess the potential of 4-m resolution multispectral data for coral reef habitat mapping. Complexity of reef environments, established by field observation, ranged from 3 to 15 classes of benthic habitats containing various combinations of sediments, carbonate pavement, seagrass, algae, and corals in different geomorphologic zones (forereef, lagoon, patch reef, reef flats). Processing included corrections for sea surface roughness and bathymetry, unsupervised or supervised classification, and accuracy assessment based on ground-truth data. IKONOS classification results were compared with classified Landsat 7 imagery for simple to moderate complexity of reef habitats (5–11 classes). For both sensors, overall accuracies of the classifications show a general linear trend of decreasing accuracy with increasing habitat complexity. The IKONOS sensor performed better, with a 15–20% improvement in accuracy compared to Landsat. For IKONOS, overall accuracy was 77% for 4–5 classes, 71% for 7–8 classes, 65% in 9–11 classes, and 53% for more than 13 classes. The Landsat classification accuracy was systematically lower, with an average of 56% for 5–10 classes. Within this general trend, inter-site comparisons and specificities demonstrate the benefits of different approaches. Pre-segmentation of the different geomorphologic zones and depth correction provided different advantages in different environments. Our results help guide scientists and managers in applying IKONOS-class data for coral reef mapping applications.

DOI

10.1016/j.rse.2003.04.005

Volume

88

Issue

1-2

First Page

128

Last Page

143

Comments

©2003 Elsevier Inc. All rights reserved.

Additional Comments

NASA grant #s: NAG5-10908, NAG-3446

This document is currently not available here.

Peer Reviewed

Find in your library

Share

COinS